去掉g.Totals.AddDef("入库单号",AggregateEnum.Count, "入库单数")
改为动态添加列进行代码统计
DataTables("统计表1").DataCols.Add("入库单数",Gettype(integer))
For Each dr As datarow In DataTables("统计表1").DataRows
dim d as date = new date(val(dr("年")),val(dr("月")),1)
dr("入库单数") = DataTables("入库单").GetValues("入库单号","入库日期 >='" & d & "' and 入库日期 < '" & d.AddMonths(1) & "'").Count
Next